Skin aging in the face involves physiological changes in the underlying tissues and is manifested as visible signs such as dryness, laxity, and wrinkles. The results from this study enrolling women who had undergone both natural and photoaging showed that daily supplementation with BCC counteracts some of these changes, as their facial skin presented with fewer visible aging signs.
Daily ingestion of BCC for 12 weeks led to a significant decrease in facial lines and wrinkles as well as in skin dryness and scaling. Improvement of these visible aging signs appears to be correlated with physiological changes in the metabolism of molecules comprising the epidermal and dermal tissues. First, the amount of hemoglobin was elevated in the dermis, implying that blood circulation through the microvasculature in the facial skin improved. As blood carries oxygen, nutrients, and growth factors to the tissue while removing metabolic wastes, improved microcirculation may lead to enhanced homeostasis of the skin. For example, efficient delivery of oxygen and nutrients to the dermis can nourish resident cells, including the dermal fibroblasts, while the structure of dermal ECM may resist various stresses caused by the oxidative aging process.
During the first 6 weeks, there was a significant increase in global fine lines and wrinkles. The cause of this initial worsening of facial aging signs was not clear. Potential factors involved include the physiology (eg, menstruation cycle) of the subjects, seasonal change, or other confounding factors. A placebo-controlled clinical trial is required to exclude these factors in revealing the true effect of BCC.
Second, a significant decrease in skin scaling and dryness appeared to be accompanied by an increase in the water content of the stratum corneum by 8.0% at week 12 from baseline values. However, this increase in hydration level was not significant, suggesting that multiple factors contribute to skin scaling and dryness. Interestingly, although the retention of water molecules in skin tissues is primarily mediated by HA, there is evidence that collagen fibrils may help hydrate the skin, as intake of hydrolyzed collagen protected mice against dermal dehydration.15
It can be speculated that improved health of the epidermis may be due to the effect of daily use of Camay soap. Camay bar soap is primarily used in clinical studies for subject compliance reasons, as it properly cleanses the skin without over-drying or irritation to the skin. A blinded, controlled study should be conducted to normalize any effect from the use of Camay.27
Third, ingestion of BCC was accompanied by increased collagen content in the dermis. Unlike other efficacy parameters, however, its increase was significant at week 6, but not at week 12. It was not clear why the effect of BCC dampened as the study progressed. Seasonal or dietary factors may have been involved. A controlled study including more subjects is needed to verify the effects of BCC not only on collagen content but also on the content of diverse skin molecules and facial aging signs.
Despite its limited effect on collagen content, BCC supplementation appeared to affect metabolic balance between biosynthesis of collagen type I and/or type III by dermal fibroblasts and their degradation by MMPs. This is intriguing because collagen present in BCC is predominantly type II, as it is extracted from chicken sternal cartilage which belongs to articular or hyaline cartilage. One of the major constituents of BCC is hydrolyzed collagen type II. Interestingly, both hydrolyzed collagen type II derived from chicken sternal cartilage, and hydrolyzed collagen type I derived from bovine skin, stimulate chondrocytes to produce collagen type II in vitro,11
which was likely due to a high level of homology in their amino acid sequences. Additionally, the Pro-Hyp dipeptide, a major peptide form present in the human blood following the ingestion of either the hydrolyzed chicken cartilage extract or hydrolyzed collagen derived from bovine skin, was shown to stimulate human dermal fibroblasts to produce HA in vitro.12
It remains unknown whether the dipeptide or other biologically active compounds derived from hydrolyzed chicken cartilage extract can directly stimulate dermal fibroblasts for de novo biosynthesis of collagen type I, which is most abundant in the skin dermis.
This study provided preliminary evidence that ingestion of BCC, a hydrolyzed chicken sternal cartilage extract, affects aging-associated physiological processes and reduces visible aging signs in the face. A controlled, long-term human study as well as in vitro studies is necessary to verify the antiaging effect of BCC supplement and to better understand its potential mechanisms.